This invention relates generally to a machine for harvesting crops in a field and, more particularly, to a split spacer ring in a cutterbar drive power takeoff that facilitates disassembly of the drive.
In modern crop harvesting machines, such as those having rotary disc cutterbars, one or more power take-off (PTO) shafts driving the cutterbar extend through the crop flow path downstream of the cutting location. Debris from the crop stream is prone to wrapping around these rotating shafts and potentially binding the shafts. Anti-wrap shields are often fitted around these shafts to reduce the debris accumulations and to protect seals where the shafts enter the cutterbar drive or gearbox. A stationary anti-wrap shield fits inside a cup-like structure on the lower side of the gearbox to form a labyrinth seal to protect the gearbox seal from damage due to upwardly migrating crop debris on the shaft. Crop conveying drums may also be connected directly to the drive shaft for further reducing crop debris accumulation on the shaft.
Removal of the cutterbar drive PTO shaft, drums, or any of the cutterbar components below the PTO for repair or replacement requires telescoping the shaft upward on the gearbox shaft and then angled outwardly at the bottom to clear the top of the cutterbar drive connection. Telescoping the PTO shaft upward requires that the cup-like portion of the labyrinth seal also telescope upward relative to the anti-wrap shield. However, the cup tends to fill with crop dust which can impede upward displacement of the cup and thus prevent shaft disassembly. Tight labyrinth clearances prevent dust removal with the structure in place.
Accordingly, it would be desirable to provide an easily removable spacer as part of the labyrinth shield structure that device that would, once removed, permit upward telescoping movement of the drive shaft to allow driveshaft removal to overcome the above problems and limitations. Further advantages would be realized by an easily removable spacer ring that could ease assembly of other components on the PTO drive shaft by providing additional axial clearance along the shaft when the spacer ring is removed.